It's easy to fall into the trap of thinking you need to be prettier if you want to be an actor or actress. It turns out, though, that most important thespians aren't conventionally pretty (Marlon Brando, Julia Roberts, Angelina Jolie, Geena Davis, Morgan Freeman…)

It's easy for a retailer or a freelancer to believe that the best way to succeed is to be cheap. But just about every important brand (and every successful freelancer) didn't get that way by being the cheapest.

And anyone who has been through high school has been reminded how important it is to be well-rounded. But Nobel Prize winners, successful NGO founders and just about everyone you admire didn't get that way by being mediocre at a lot of things.

Pretty, cheap and well-rounded are seductive ways to hide out in a crowd. But they're not the path to doing work that matters.